Riddle us this: What do Meg Ryan, Marisa Tomei, and rising stars Julianne Moore and Parker Posey all have in common? The answer: As the World Turns, where their soap opera personae were often canny predictors of casting to come.

Meg Ryan (1982-84), the lovelorn lady next door of Sleepless in Seattle and French Kiss, played Betsy Stewart, a lovelorn girl next door attracted to destructive men.

Julianne Moore (1985-88), a troubled wife in Short Cuts and Safe and a blissful one in the July comedy Nine Months, won a Daytime Emmy in 1988 for her dual role as half sisters Frannie and Sabrina Hughes, the former a beloved daughter, the latter a tortured artist who steals her sister’s fiance.

Parker Posey (1991-92), a manipulative vamp in Dazed and Confused and Party Girl, played Tess Shelby, manipulative vamp.

What makes the CBS soap such a stepping-stone? No one’s offering theories. But Posey says the most important lesson she gleaned from ATWT was how to sleep on the job: ”I learned how to lie down so that you don’t have a wrinkled face and your hair’s not a mess.” Naps — the key to success?